The most crucial and eternally consequential human need is the need to be at peace with God.
The Bible teaches that we naturally fail to achieve that peace. We are born under the curse of Adam (Romans 5:12). This means we are born with a sinful nature which leaves us at war with God.
The good news is that despite our sinfulness, God desires that all people be saved and come to the knowledge of the truth (1 Timothy 2:4). To make that possible, God the Son, Jesus Christ, became man, lived the life of perfect obedience we could not, and died on a cross. On this cross he “became sin” for us, so that we could become the “righteousness of God” (2 Corinthians 5:21). On this cross, Jesus earned our peace with God by the blood he shed there (Colossians 1:20). Jesus took the punishment we deserved, and paid the debt we owed God to earn the forgiveness we needed.
We find this good news (a.k.a. the Gospel) in God’s Word, the Bible. As we hear hear or read it, God sends his Holy Spirit to show us our sin and need for him, and gives us faith in Jesus’ rescuing work. As John 3:16 says, “Whosoever believes in him, shall not perish but have eternal life.” The “work we need to do” is to believe in Jesus, whom God sent (John 6:29).
All who believe (i.e. have faith in or trust) in the Gospel are forgiven of their sin, saved from eternal death in hell, assured friendship with God and adoption into his family, given the Holy Spirit to guide and lead them, and are promised a bodily resurrection brought about at Christ’s return, and are granted eternal life (John 3:16, Ephesians 1:3-14).
Our prayer is that God would grant you this faith, and that you may enjoy peace with him!